This invention relates to a sheet handling apparatus. In particular, the invention relates to an apparatus for transporting sheets in a controlled manner, whereby the time at which a sheet arrives at a certain point may be adjusted, or the orientation of a sheet relative to the direction of travel may be adjusted.
The invention has application, for example, to a currency note stacking mechanism included in a cash dispenser unit of an automated teller machine (ATM). As is well known, in operation of an ATM a user inserts a customer identifying card into the machine and then enters certain data (such as codes, quantity of currency required, type of transaction, etc.) upon one or more keyboards associated with the machine. The machine will then process the transaction, update the user's account to reflect the current transaction, dispense cash, when requested, from one or more currency cassettes mounted in the machine, and return the card to the user as part of a routine operation.
A cash dispenser unit of an ATM conventionally includes at least one note picking mechanism for extracting notes one by one from a currency cassette, and a stacking and presenting mechanism for accumulating the extracted notes into a stack and then feeding the stack of notes to a delivery port or exit slot in the ATM from where the stack may be removed by a user of the ATM.
A well known type of currency note stacking mechanism includes a stacking wheel which continuously rotates in operation and which incorporates a series of curved tines. Notes are fed one by one to the stacking wheel, and they successively enter compartments formed between adjacent tines and are carried partly around the axis of the wheel before being stripped from the wheel by a stationary pick-off member and formed into a stack.
In a known cash dispenser mechanism having a stacking wheel, the note picking means and the stacking wheel are operated in synchronism so that in normal operation successive notes arriving at the stacking wheel are fed into successive compartments of the wheel. Certain problems have been experienced with such known mechanisms. For example, if the leading edge of a picked note is folded, then this leading edge may hit the end of one of the tines instead of being inserted into one of the compartments, thereby possibly causing the note to fail to be dispensed to a customer, or possibly damaging the note or causing jamming of the stacking wheel or some associated mechanism to occur. Also, if the note picking means incorporates a friction feed means, then it is possible that in some situations slippage between a picked note and the feeding means may occur, which may again cause the leading edge of the note to hit the end of one of the tines of the stacking wheel.
Another application of the present invention is to a system for verifying currency notes. A note verification system often includes detector means for generating an electric signal in response to the recognition of a feature or the absence of a feature on a note and comparing this signal with a standard signal. For proper operation of such a system it is important that a note should arrive at the detector means with an accurately correct orientation relative to the detector means. From U.K. patent application No. 2128169A there is known a mechanism for removing skew from a note prior to the note arriving at a detector station of a note verification system. In operation of this known mechanism, if skew in a note is detected, this note is diverted into a looped path comprising two belt transport means, one of which provides a longer path length than the other. This looped path provides a fixed amount of skew correction for each circulation of the note. This known skew correction apparatus has the disadvantages that means must be provided for ensuring that a skewed note enters the looped path with its leading corner positioned for engagement by the longer belt means, and that only a fixed amount of skew can be removed for each circulation of a note.